added an environment luminaire, changed the sky.cpp implementation so that it forwards to envmap.cpp

metadata
Wenzel Jakob 2011-07-28 02:52:31 +02:00
parent e379ffda42
commit 8e448eaf6c
12 changed files with 308 additions and 242 deletions

View File

@ -9,6 +9,9 @@
<!-- Test the environment map luminaire -->
<luminaire type="envmap">
<string name="filename" value="data/tests/envmap.exr"/>
<transform name="toWorld">
<rotate x="1" angle="40"/>
</transform>
</luminaire>
<!-- Make sure that the scene actually contains something -->

Binary file not shown.

Before

Width:  |  Height:  |  Size: 204 KiB

After

Width:  |  Height:  |  Size: 196 KiB

Binary file not shown.

Before

Width:  |  Height:  |  Size: 209 KiB

After

Width:  |  Height:  |  Size: 200 KiB

View File

@ -55,17 +55,17 @@ public:
* Returns false if the computed position is not visible through
* the film's crop window
*/
virtual bool positionToSample(const Point &p, Point2 &sample) const = 0;
virtual bool positionToSample(const Point &p, Point2 &sample) const;
/// Does generateRay() expect a proper lens sample?
virtual bool needsLensSample() const = 0;
virtual bool needsLensSample() const;
/// Does generateRay() expect a proper time sample?
inline bool needsTimeSample() const { return m_shutterOpenTime > 0; }
/// Return the time value of the shutter opening event
inline Float getShutterOpen() const { return m_shutterOpen; }
/// Return the length, for which the shutter remains open
inline Float getShutterOpenTime() const { return m_shutterOpenTime; }
@ -114,7 +114,7 @@ public:
* Calculate the pixel area density at a position on the image plane.
* Returns zero for cameras with an infinitesimal sensor (e.g. pinhole cameras).
*/
virtual Float areaDensity(const Point2 &p) const = 0;
virtual Float areaDensity(const Point2 &p) const;
//! @}
// =============================================================
@ -175,6 +175,10 @@ public:
/// Return the properties of this camera
inline const Properties &getProperties() const { return m_properties; }
/** \brief Configure the object (called _once_ after construction
and addition of all child ConfigurableObjects. */
virtual void configure();
//! @}
// =============================================================

View File

@ -157,7 +157,7 @@ public:
* \brief Return an estimate of the total amount of power emitted
* by this luminaire.
*/
virtual Spectrum getPower() const = 0;
virtual Spectrum getPower() const;
/// Is this luminaire intersectable (e.g. can it be encountered by a tracing a ray)?
inline bool isIntersectable() const { return m_intersectable; }
@ -194,7 +194,7 @@ public:
* Sampling is ideally done with respect to solid angle at \c p.
*/
virtual void sample(const Point &p,
LuminaireSamplingRecord &lRec, const Point2 &sample) const = 0;
LuminaireSamplingRecord &lRec, const Point2 &sample) const;
/**
* \brief Calculate the solid angle density for generating this sample
@ -204,7 +204,7 @@ public:
* are considered in the query. Otherwise, they are left out.
*/
virtual Float pdf(const Point &p,
const LuminaireSamplingRecord &lRec, bool delta) const = 0;
const LuminaireSamplingRecord &lRec, bool delta) const;
//! @}
// =============================================================
@ -225,7 +225,7 @@ public:
* of the spatial and directional sampling densities.
*/
virtual void sampleEmission(EmissionRecord &eRec,
const Point2& areaSample, const Point2 &dirSample) const = 0;
const Point2& areaSample, const Point2 &dirSample) const;
/**
* \brief Sample only the spatial part of the emission sampling strategy
@ -239,7 +239,7 @@ public:
* spatially dependent emittance component will be stored in \c eRec.
*/
virtual void sampleEmissionArea(EmissionRecord &lRec,
const Point2 &sample) const = 0;
const Point2 &sample) const;
/**
* \brief Sample only the directional part of the emission sampling strategy
@ -252,7 +252,7 @@ public:
* component of the radiant emittance obtained in \ref sampleEmissionArea.
*/
virtual Spectrum sampleEmissionDirection(EmissionRecord &lRec,
const Point2 &sample) const = 0;
const Point2 &sample) const;
/**
* \brief Given an emitted particle, populate the emission record with the
@ -261,13 +261,13 @@ public:
* When \c delta is set to true, only components with a Dirac delta density
* are considered in the query. Otherwise, they are left out.
*/
virtual void pdfEmission(EmissionRecord &eRec, bool delta) const = 0;
virtual void pdfEmission(EmissionRecord &eRec, bool delta) const;
/**
* \brief Evaluate the spatial component of the radiant emittance at a
* point on the luminaire (ignoring any directional variations).
*/
virtual Spectrum evalArea(const EmissionRecord &eRec) const = 0;
virtual Spectrum evalArea(const EmissionRecord &eRec) const;
/**
* \brief Evaluate the directional emission distribution of this light source
@ -275,7 +275,7 @@ public:
*
* This function is normalized so that it integrates to one.
*/
virtual Spectrum evalDirection(const EmissionRecord &eRec) const = 0;
virtual Spectrum evalDirection(const EmissionRecord &eRec) const;
//! @}
// =============================================================

View File

@ -2,5 +2,6 @@ Import('env', 'plugins')
plugins += env.SharedLibrary('perspective', ['perspective.cpp'])
plugins += env.SharedLibrary('orthographic', ['orthographic.cpp'])
plugins += env.SharedLibrary('environment', ['environment.cpp'])
Export('plugins')

104
src/cameras/environment.cpp Normal file
View File

@ -0,0 +1,104 @@
/*
This file is part of Mitsuba, a physically based rendering system.
Copyright (c) 2007-2011 by Wenzel Jakob and others.
Mitsuba is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License Version 3
as published by the Free Software Foundation.
Mitsuba is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mitsuba/render/camera.h>
#include <mitsuba/core/statistics.h>
MTS_NAMESPACE_BEGIN
static StatsCounter cameraRays("General", "Camera ray generations");
/**
* Simple environment camera model
* - based on the version in PBRT
*/
class EnvironmentCamera : public Camera {
public:
EnvironmentCamera(const Properties &props)
: Camera(props) { }
EnvironmentCamera(Stream *stream, InstanceManager *manager)
: Camera(stream, manager) {
configure();
}
void serialize(Stream *stream, InstanceManager *manager) const {
Camera::serialize(stream, manager);
}
void configure() {
Camera::configure();
Vector2i filmSize = m_film->getSize();
m_invResolution = Point2(
1.0f / filmSize.x,
1.0f / filmSize.y
);
}
/**
* Cartesian-to-spherical coordinate mapping with
* v=0 => Y=1
*/
Vector squareToSphereY(Float u, Float v) const {
Float cosTheta = std::cos(v * M_PI),
sinTheta = std::sin(v * M_PI),//std::sqrt(1-cosTheta*cosTheta),
phi = u * 2 * M_PI,
cosPhi = std::cos(phi), sinPhi = std::sin(phi);
return Vector(
sinTheta * sinPhi, cosTheta, -sinTheta*cosPhi);
}
/* Corresponding reverse mapping */
Point2 sphereToSquareY(const Vector &d) const {
Float u = std::atan2(d.x,-d.z) * (0.5f * INV_PI),
v = std::acos(std::max((Float) -1.0f,
std::min((Float) 1.0f, d.y))) / M_PI;
if (u < 0)
u += 1;
return Point2(u, v);
}
void generateRay(const Point2 &dirSample, const Point2 &lensSample,
Float timeSample, Ray &ray) const {
++cameraRays;
Float u = dirSample.x * m_invResolution.x,
v = dirSample.y * m_invResolution.y;
Vector direction = squareToSphereY(u, v);
Point2 uvPrime = sphereToSquareY(direction);
if ((std::abs(uvPrime.x-u) > Epsilon || std::abs(uvPrime.y-v)>Epsilon) && u < 1 && v < 1 && u > 0 && v > 0)
cout << uvPrime.toString() << " vs " << u << ", " << v << endl;
/* Construct ray in camera space */
Ray localRay(Point(0.0f), direction,
m_shutterOpen + m_shutterOpenTime * timeSample);
/* Transform into world space */
m_cameraToWorld(localRay, ray);
}
MTS_DECLARE_CLASS()
private:
Point2 m_invResolution;
};
MTS_IMPLEMENT_CLASS_S(EnvironmentCamera, false, Camera)
MTS_EXPORT_PLUGIN(EnvironmentCamera, "Environment camera");
MTS_NAMESPACE_END

View File

@ -56,6 +56,23 @@ void Camera::setParent(ConfigurableObject *parent) {
// the camera subtree needs to be serialized by itself.
}
void Camera::configure() {
if (m_film == NULL) {
/* Instantiate an EXR film by default */
m_film = static_cast<Film*> (PluginManager::getInstance()->
createObject(MTS_CLASS(Film), Properties("exrfilm")));
m_film->configure();
}
if (m_sampler == NULL) {
/* No sampler has been selected - load an independent filter with 4 samples/pixel by default */
Properties props("independent");
props.setInteger("sampleCount", 4);
m_sampler = static_cast<Sampler *> (PluginManager::getInstance()->
createObject(MTS_CLASS(Sampler), props));
m_sampler->configure();
}
}
Point Camera::getPosition(const Point2 &sample) const {
return m_position; // default impl.
}
@ -107,6 +124,22 @@ void Camera::addChild(const std::string &name, ConfigurableObject *child) {
}
}
bool Camera::positionToSample(const Point &p, Point2 &sample) const {
Log(EError, "%s::positionToSample(): not implemented!",
getClass()->getName().c_str());
return false;
}
Float Camera::areaDensity(const Point2 &p) const {
Log(EError, "%s::areaDensity(): not implemented!",
getClass()->getName().c_str());
return 0.0f;
}
bool Camera::needsLensSample() const {
return false;
}
ProjectiveCamera::ProjectiveCamera(Stream *stream, InstanceManager *manager)
: Camera(stream, manager) {
m_cameraToScreen = Transform(stream);
@ -124,21 +157,7 @@ ProjectiveCamera::ProjectiveCamera(const Properties &props) : Camera(props) {
}
void ProjectiveCamera::configure() {
if (m_film == NULL) {
/* Instantiate an EXR film by default */
m_film = static_cast<Film*> (PluginManager::getInstance()->
createObject(MTS_CLASS(Film), Properties("exrfilm")));
m_film->configure();
}
if (m_sampler == NULL) {
/* No sampler has been selected - load an independent filter with 4 samples/pixel by default */
Properties props("independent");
props.setInteger("sampleCount", 4);
m_sampler = static_cast<Sampler *> (PluginManager::getInstance()->
createObject(MTS_CLASS(Sampler), props));
m_sampler->configure();
}
Camera::configure();
m_aspect = (Float) m_film->getSize().x / (Float) m_film->getSize().y;
}

View File

@ -103,6 +103,61 @@ Luminaire *Luminaire::getElement(int i) {
return NULL;
}
void Luminaire::sampleEmission(EmissionRecord &eRec,
const Point2& areaSample, const Point2 &dirSample) const {
Log(EError, "%s::areaDensity(): not implemented!",
getClass()->getName().c_str());
}
void Luminaire::sampleEmissionArea(EmissionRecord &lRec,
const Point2 &sample) const {
Log(EError, "%s::sampleEmissionArea(): not implemented!",
getClass()->getName().c_str());
}
Spectrum Luminaire::sampleEmissionDirection(EmissionRecord &lRec,
const Point2 &sample) const {
Log(EError, "%s::sampleEmissionDirection(): not implemented!",
getClass()->getName().c_str());
return Spectrum(0.0f);
}
void Luminaire::pdfEmission(EmissionRecord &eRec, bool delta) const {
Log(EError, "%s::pdfEmission(): not implemented!",
getClass()->getName().c_str());
}
Spectrum Luminaire::evalArea(const EmissionRecord &eRec) const {
Log(EError, "%s::evalArea(): not implemented!",
getClass()->getName().c_str());
return Spectrum(0.0f);
}
Spectrum Luminaire::evalDirection(const EmissionRecord &eRec) const {
Log(EError, "%s::evalDirection(): not implemented!",
getClass()->getName().c_str());
return Spectrum(0.0f);
}
void Luminaire::sample(const Point &p,
LuminaireSamplingRecord &lRec, const Point2 &sample) const {
Log(EError, "%s::sample(): not implemented!",
getClass()->getName().c_str());
}
Float Luminaire::pdf(const Point &p,
const LuminaireSamplingRecord &lRec, bool delta) const {
Log(EError, "%s::pdf(): not implemented!",
getClass()->getName().c_str());
return 0.0f;
}
Spectrum Luminaire::getPower() const {
Log(EError, "%s::getPower(): not implemented!",
getClass()->getName().c_str());
return Spectrum(0.0f);
}
std::string EmissionRecord::toString() const {
std::ostringstream oss;
oss << "EmissionRecord[" << std::endl

View File

@ -25,8 +25,6 @@
#include <mitsuba/hw/gputexture.h>
#include <mitsuba/hw/gpuprogram.h>
//#define SAMPLE_UNIFORMLY 1
MTS_NAMESPACE_BEGIN
/**
@ -39,10 +37,17 @@ class EnvMapLuminaire : public Luminaire {
public:
EnvMapLuminaire(const Properties &props) : Luminaire(props) {
m_intensityScale = props.getFloat("intensityScale", 1);
m_path = Thread::getThread()->getFileResolver()->resolve(props.getString("filename"));
Log(EInfo, "Loading environment map \"%s\"", m_path.leaf().c_str());
ref<Stream> is = new FileStream(m_path, FileStream::EReadOnly);
ref<Bitmap> bitmap = new Bitmap(Bitmap::EEXR, is);
ref<Bitmap> bitmap;
if (props.hasProperty("bitmap")) {
bitmap = reinterpret_cast<Bitmap *>(props.getData("bitmap").ptr);
m_path = "<unknown>";
} else {
m_path = Thread::getThread()->getFileResolver()->resolve(props.getString("filename"));
Log(EInfo, "Loading environment map \"%s\"", m_path.leaf().c_str());
ref<Stream> is = new FileStream(m_path, FileStream::EReadOnly);
bitmap = new Bitmap(Bitmap::EEXR, is);
}
m_mipmap = MIPMap::fromBitmap(bitmap, MIPMap::ETrilinear,
MIPMap::ERepeat, 0.0f, Spectrum::EIlluminant);
@ -97,9 +102,11 @@ public:
void configure() {
int mipMapLevel = std::min(3, m_mipmap->getLevels()-1);
m_pdfResolution = m_mipmap->getLevelResolution(mipMapLevel);
m_pdfInvResolution = Vector2(1.0f / m_pdfResolution.x, 1.0f / m_pdfResolution.y);
m_pdfInvResolution = Vector2(1.0f / m_pdfResolution.x,
1.0f / m_pdfResolution.y);
Log(EDebug, "Creating a %ix%i sampling density", m_pdfResolution.x, m_pdfResolution.y);
Log(EDebug, "Creating a %ix%i sampling density",
m_pdfResolution.x, m_pdfResolution.y);
const Spectrum *coarseImage = m_mipmap->getImageData(mipMapLevel);
int index = 0;
m_pdf = DiscretePDF(m_pdfResolution.x * m_pdfResolution.y);
@ -133,35 +140,45 @@ public:
return m_average * m_surfaceArea * M_PI;
}
/// Sample an emission direction
Vector sampleDirection(Point2 sample, Float &pdf, Spectrum &value) const {
#if defined(SAMPLE_UNIFORMLY)
pdf = 1.0f / (4*M_PI);
Vector d = squareToSphere(sample);
value = Le(-d);
return d;
#else
int idx = m_pdf.sampleReuse(sample.x, pdf);
int row = idx / m_pdfResolution.x;
int col = idx - m_pdfResolution.x * row;
Float x = col + sample.x, y = row + sample.y;
value = m_mipmap->triangle(0, x * m_pdfInvResolution.x, y * m_pdfInvResolution.y)
* m_intensityScale;
Float theta = m_pdfPixelSize.y * y, phi = m_pdfPixelSize.x * x - M_PI;
Float sinTheta = std::sin(theta), cosTheta = std::cos(theta);
Float sinPhi = std::sin(phi), cosPhi = std::cos(phi);
value = m_mipmap->triangle(0, x * m_pdfInvResolution.x,
y * m_pdfInvResolution.y) * m_intensityScale;
Float theta = m_pdfPixelSize.y * y,
phi = m_pdfPixelSize.x * x;
/* Spherical-to-cartesian coordinate mapping with
theta=0 => Y=1 */
Float cosTheta = std::cos(theta),
sinTheta = std::sqrt(1-cosTheta*cosTheta),
cosPhi = std::cos(phi),
sinPhi = std::sin(phi);
Vector sampledDirection(sinTheta * sinPhi,
cosTheta, -sinTheta*cosPhi);
pdf = pdf / (m_pdfPixelSize.x * m_pdfPixelSize.y * sinTheta);
return m_luminaireToWorld(Vector(
-sinTheta * sinPhi, -cosTheta, sinTheta*cosPhi));
#endif
return m_luminaireToWorld(-sampledDirection);
}
Point2 fromSphere(const Vector &d) const {
Float u = std::atan2(d.x,-d.z) * (0.5f * INV_PI),
v = std::acos(std::max((Float) -1.0f,
std::min((Float) 1.0f, d.y))) * INV_PI;
if (u < 0)
u += 1;
return Point2(u, v);
}
inline Spectrum Le(const Vector &direction) const {
const Vector d = m_worldToLuminaire(direction);
const Float u = .5f * (1 + std::atan2(d.x,-d.z) / M_PI);
const Float v = std::acos(std::max((Float) -1.0f,
std::min((Float) 1.0f, d.y))) / M_PI;
return m_mipmap->triangle(0, u, v) * m_intensityScale;
Point2 uv = fromSphere(m_worldToLuminaire(direction));
return m_mipmap->triangle(0, uv.x, uv.y)
* m_intensityScale;
}
inline Spectrum Le(const Ray &ray) const {
@ -183,21 +200,17 @@ public:
}
Float pdf(const Point &p, const LuminaireSamplingRecord &lRec, bool delta) const {
#if defined(SAMPLE_UNIFORMLY)
return 1.0f / (4*M_PI);
#else
const Vector d = m_worldToLuminaire(-lRec.d);
const Float x = .5f * (1 + std::atan2(d.x,-d.z) / M_PI) * m_pdfResolution.x;
const Float y = std::acos(std::max((Float) -1.0f, std::min((Float) 1.0f, d.y)))
/ M_PI * m_pdfResolution.y;
int xPos = std::min(std::max((int) std::floor(x), 0), m_pdfResolution.x-1);
int yPos = std::min(std::max((int) std::floor(y), 0), m_pdfResolution.y-1);
const Vector d = m_worldToLuminaire(-lRec.d);
Point2 xy = fromSphere(d);
xy.x *= m_pdfResolution.x;
xy.y *= m_pdfResolution.y;
int xPos = std::min(std::max((int) std::floor(xy.x), 0), m_pdfResolution.x-1);
int yPos = std::min(std::max((int) std::floor(xy.y), 0), m_pdfResolution.y-1);
Float pdf = m_pdf[xPos + yPos * m_pdfResolution.x];
Float sinTheta = std::sqrt(std::max((Float) Epsilon, 1-d.y*d.y));
return pdf / (m_pdfPixelSize.x * m_pdfPixelSize.y * sinTheta);
#endif
}
/**
@ -386,7 +399,9 @@ public:
<< endl
<< "vec3 " << evalName << "_background(vec3 wo) {" << endl
<< " vec3 d = normalize((" << evalName << "_worldToLuminaire * vec4(wo, 0.0)).xyz);" << endl
<< " float u = 0.5 * (1.0 + atan(d.x, -d.z) * 0.318309);" << endl
<< " float u = atan(d.x, -d.z) * 0.15915;" << endl
<< " if (u < 0.0)" << endl
<< " u += 1.0;" << endl
<< " float v = acos(max(-1.0, min(1.0, d.y))) * 0.318309;" << endl
// The following is not very elegant, but necessary to trick GLSL
// into doing correct texture filtering across the u=0 to u=1 seam.

View File

@ -17,9 +17,8 @@
*/
#include <mitsuba/render/scene.h>
#include <mitsuba/core/util.h>
#include <mitsuba/core/bitmap.h>
#include <mitsuba/core/fstream.h>
#include <mitsuba/core/plugin.h>
#define SAMPLE_UNIFORMLY 1
@ -141,6 +140,15 @@ MTS_NAMESPACE_BEGIN
* and the moon dominate. The model also currently does not handle cloudy skies.
* The implementation in Mitsuba is based on code by Preetham et al. It was
* ported by Tom Kazimiers.
*
* \begin{xml}[caption={Rotating the sky luminaire for scenes that use $Z$ as
* the ``up'' direction}, label=lst:sky-up]
* <luminaire type="sky">
* <transform name="toWorld">
* <rotate x="1" angle="90"/>
* </transform>
* </luminaire>
* \end{xml}
*/
class SkyLuminaire : public Luminaire {
public:
@ -151,12 +159,6 @@ public:
*/
SkyLuminaire(const Properties &props)
: Luminaire(props) {
/* Transformation from the luminaire's local coordinates to
* world coordiantes */
m_luminaireToWorld =
props.getTransform("toWorld", Transform());
m_worldToLuminaire = m_luminaireToWorld.inverse();
m_scale = props.getFloat("scale", Float(1.0));
m_turbidity = props.getFloat("turbidity", Float(3.0));
if (m_turbidity < 1 || m_turbidity > 30)
@ -242,7 +244,6 @@ public:
m_zenithL = (4.0453f * m_turbidity - 4.9710f) * std::tan(chi)
- 0.2155f * m_turbidity + 2.4192f;
cout << toString() << endl;
/* Evaluate quadratic polynomials to find the Perez sky
* model coefficients for the x, y and luminance components */
@ -263,12 +264,20 @@ public:
m_perezY[2] = -0.00792f * m_turbidity + 0.21023f;
m_perezY[3] = -0.04405f * m_turbidity - 1.65369f;
m_perezY[4] = -0.01092f * m_turbidity + 0.05291f;
}
bool isCompound() const {
return true;
}
Luminaire *getElement(int i) {
if (i != 0)
return NULL;
int thetaBins = m_resolution, phiBins = m_resolution*2;
ref<Bitmap> bitmap = new Bitmap(phiBins, thetaBins, 128);
bitmap->clear();
Point2 factor(M_PI / thetaBins, (2*M_PI) / phiBins);
float *target = bitmap->getFloatData();
for (int i=0; i<thetaBins; ++i) {
Float theta = (i+.5f)*factor.x;
for (int j=0; j<phiBins; ++j) {
@ -276,18 +285,31 @@ public:
Spectrum s = getSkySpectralRadiance(theta, phi) * m_scale;
Float r, g, b;
s.toLinearRGB(r, g, b);
bitmap->getFloatData()[(j+i*phiBins)*4 + 0] = r;
bitmap->getFloatData()[(j+i*phiBins)*4 + 1] = g;
bitmap->getFloatData()[(j+i*phiBins)*4 + 2] = b;
bitmap->getFloatData()[(j+i*phiBins)*4 + 3] = 1;
*target++ = r; *target++ = g;
*target++ = b; *target++ = 1;
}
}
/* Instantiate a nested envmap plugin */
Properties props("envmap");
Properties::Data bitmapData;
bitmapData.ptr = (uint8_t *) bitmap.get();
bitmapData.size = sizeof(Bitmap);
props.setData("bitmap", bitmapData);
props.setTransform("toWorld", m_luminaireToWorld);
props.setFloat("samplingWeight", m_samplingWeight);
Luminaire *luminaire = static_cast<Luminaire *>(
PluginManager::getInstance()->createObject(
MTS_CLASS(Luminaire), props));
luminaire->configure();
return luminaire;
}
Vector toSphere(Float theta, Float phi) const {
/* Spherical-to-cartesian coordinate mapping with
theta=0 => Y=1 */
Float cosTheta = std::cos(theta), sinTheta = std::sin(theta),
Float cosTheta = std::cos(theta),
sinTheta = std::sqrt(1-cosTheta*cosTheta),
cosPhi = std::cos(phi), sinPhi = std::sin(phi);
return m_luminaireToWorld(Vector(
sinTheta * sinPhi, cosTheta, -sinTheta*cosPhi));
@ -340,149 +362,6 @@ public:
m_phiS = sunPos.y;
}
void preprocess(const Scene *scene) {
/* Get the scene's bounding sphere and slightly enlarge it */
m_bsphere = scene->getBSphere();
m_bsphere.radius *= 1.01f;
}
Spectrum getPower() const {
/* TODO */
return m_average * (M_PI * 4 * M_PI
* m_bsphere.radius * m_bsphere.radius);
}
inline Spectrum Le(const Vector &direction) const {
/* Compute sky light radiance for direction */
Vector d = normalize(m_worldToLuminaire(direction));
const Point2 sphCoords = fromSphere(d);
return getSkySpectralRadiance(sphCoords.x, sphCoords.y) * m_scale;
}
inline Spectrum Le(const Ray &ray) const {
return Le(normalize(ray.d));
}
Spectrum Le(const LuminaireSamplingRecord &lRec) const {
return Le(-lRec.d);
}
inline void sample(const Point &p, LuminaireSamplingRecord &lRec,
const Point2 &sample) const {
lRec.d = sampleDirection(sample, lRec.pdf, lRec.value);
lRec.sRec.p = p - lRec.d * (2 * m_bsphere.radius);
}
void sample(const Intersection &its, LuminaireSamplingRecord &lRec,
const Point2 &sample) const {
SkyLuminaire::sample(its.p, lRec, sample);
}
inline Float pdf(const Point &p, const LuminaireSamplingRecord &lRec, bool delta) const {
#if defined(SAMPLE_UNIFORMLY)
return 1.0f / (4 * M_PI);
#endif
}
Float pdf(const Intersection &its, const LuminaireSamplingRecord &lRec, bool delta) const {
return SkyLuminaire::pdf(its.p, lRec, delta);
}
/**
* This is the tricky bit - we want to sample a ray that
* has uniform density over the set of all rays passing
* through the scene.
* For more detail, see "Using low-discrepancy sequences and
* the Crofton formula to compute surface areas of geometric models"
* by Li, X. and Wang, W. and Martin, R.R. and Bowyer, A.
* (Computer-Aided Design vol 35, #9, pp. 771--782)
*/
void sampleEmission(EmissionRecord &eRec,
const Point2 &sample1, const Point2 &sample2) const {
Assert(eRec.type == EmissionRecord::ENormal);
/* Chord model - generate the ray passing through two uniformly
distributed points on a sphere containing the scene */
Vector d = squareToSphere(sample1);
eRec.sRec.p = m_bsphere.center + d * m_bsphere.radius;
eRec.sRec.n = Normal(-d);
Point p2 = m_bsphere.center + squareToSphere(sample2) * m_bsphere.radius;
eRec.d = p2 - eRec.sRec.p;
Float length = eRec.d.length();
if (length == 0) {
eRec.value = Spectrum(0.0f);
eRec.pdfArea = eRec.pdfDir = 1.0f;
return;
}
eRec.d /= length;
eRec.pdfArea = 1.0f / (4 * M_PI * m_bsphere.radius * m_bsphere.radius);
eRec.pdfDir = INV_PI * dot(eRec.sRec.n, eRec.d);
eRec.value = Le(-eRec.d);
}
void sampleEmissionArea(EmissionRecord &eRec, const Point2 &sample) const {
if (eRec.type == EmissionRecord::ENormal) {
Vector d = squareToSphere(sample);
eRec.sRec.p = m_bsphere.center + d * m_bsphere.radius;
eRec.sRec.n = Normal(-d);
eRec.pdfArea = 1.0f / (4 * M_PI * m_bsphere.radius * m_bsphere.radius);
eRec.value = Spectrum(M_PI);
} else {
/* Preview mode, which is more suitable for VPL-based rendering: approximate
the infinitely far-away source with set of diffuse point sources */
const Float radius = m_bsphere.radius * 1.5f;
Vector d = squareToSphere(sample);
eRec.sRec.p = m_bsphere.center + d * radius;
eRec.sRec.n = Normal(-d);
eRec.pdfArea = 1.0f / (4 * M_PI * radius * radius);
eRec.value = Le(d) * M_PI;
}
}
Spectrum sampleEmissionDirection(EmissionRecord &eRec, const Point2 &sample) const {
Float radius = m_bsphere.radius;
if (eRec.type == EmissionRecord::EPreview)
radius *= 1.5f;
Point p2 = m_bsphere.center + squareToSphere(sample) * radius;
eRec.d = p2 - eRec.sRec.p;
Float length = eRec.d.length();
if (length == 0.0f) {
eRec.pdfDir = 1.0f;
return Spectrum(0.0f);
}
eRec.d /= length;
eRec.pdfDir = INV_PI * dot(eRec.sRec.n, eRec.d);
if (eRec.type == EmissionRecord::ENormal)
return Le(-eRec.d) * INV_PI;
else
return Spectrum(INV_PI);
}
Spectrum evalDirection(const EmissionRecord &eRec) const {
if (eRec.type == EmissionRecord::ENormal)
return Le(-eRec.d) * INV_PI;
else
return Spectrum(INV_PI);
}
Spectrum evalArea(const EmissionRecord &eRec) const {
Assert(eRec.type == EmissionRecord::ENormal);
return Spectrum(M_PI);
}
Spectrum f(const EmissionRecord &eRec) const {
if (eRec.type == EmissionRecord::ENormal)
return Le(-eRec.d) * INV_PI;
else
return Spectrum(INV_PI);
}
void pdfEmission(EmissionRecord &eRec, bool delta) const {
}
std::string toString() const {
std::ostringstream oss;
oss << "SkyLuminaire[" << endl
@ -493,20 +372,6 @@ public:
<< "]";
return oss.str();
}
bool isBackgroundLuminaire() const {
return true;
}
Vector sampleDirection(Point2 sample, Float &pdf, Spectrum &value) const {
#if defined(SAMPLE_UNIFORMLY)
pdf = 1.0f / (4*M_PI);
Vector d = squareToSphere(sample);
value = Le(-d);
return d;
#endif
}
private:
/**
* Calculates the angle between two spherical cooridnates. All
@ -586,9 +451,9 @@ private:
MTS_DECLARE_CLASS()
protected:
Spectrum m_average;
BSphere m_bsphere;
/* Environment map resolution */
int m_resolution;
/* Constant scale factor applied to the model */
Float m_scale;
/* The turbidity of the sky ranges normally from 1 to 30.
For clear skies values in range [2,6] are useful. */
@ -606,6 +471,6 @@ protected:
};
MTS_IMPLEMENT_CLASS_S(SkyLuminaire, false, Luminaire)
MTS_EXPORT_PLUGIN(SkyLuminaire, "Sky luminaire");
MTS_EXPORT_PLUGIN(SkyLuminaire, "Preetham sky luminaire");
MTS_NAMESPACE_END

View File

@ -554,13 +554,13 @@ public:
LuminaireAdapter adapter(luminaire, sampler);
ref<ChiSquare> chiSqr = new ChiSquare(thetaBins, 2*thetaBins, 1);
chiSqr->setLogLevel(EDebug);
chiSqr->dumpTables("test.m");
// Initialize the tables used by the chi-square test
chiSqr->fill(
boost::bind(&LuminaireAdapter::generateSample, &adapter),
boost::bind(&LuminaireAdapter::pdf, &adapter, _1, _2)
);
chiSqr->dumpTables("test.m");
// (the following assumes that the distribution has 1 parameter, e.g. exponent value)
ChiSquare::ETestResult result = chiSqr->runTest(SIGNIFICANCE_LEVEL);